Stefan Esser, also known as I0n1c, the hacker behind the iOS 4.3.1 untether has created an amazing presentation on the latest iOS jailbreak techniques. Esser made the presentation for Black Hat last month.

Exploiting the iOS Kernel
The iPhone user land is locked down very tightly by kernel level protections. Therefore any sophisticated attack has to include a kernel exploit in order to completely compromise the device. Because of this our previous session titled "Targeting the iOS Kernel" already discussed how to reverse the iOS kernel in order to find kernel security vulnerabilities. Exploitation of iOS kernel vulnerabilities has not been discussed yet.

This session will introduce the audience to kernel level exploitation of iPhones. With the help of previously disclosed kernel vulnerabilities the exploitation of uninitialized kernel variables, kernel stack buffer overflows, out of bound writes and kernel heap buffer overflows will be discussed.

Furthermore the kernel patches applied by iPhone jailbreaks will be discussed in order to understand how certain security features are deactivated. A tool will be released that allows to selectively de-activate some of these kernel patches for more realistic exploit tests.